I think this papers backs up pretty well and goes into a lot more details of why it matters to focus on the flow. In fact it’s crucial that such issues that stop production including predicting and identifying demand-supply mismatch is essential for a smooth flow of operations. BUT, humans are humans and we plan for the best case scenario without giving due consideration for failure modes. Manufacturing is hardly an exception.

https://businesswales.gov.wales/sites/business-wales/files/S...